German Published Application 37 06 325, incorporated herein, discloses a control and data network that contains a master computer which transmits data to connector modules from which it can also receive information. Every connector module has a processor to which this data is supplied, which processes this data on the basis of a program, and which correspondingly drives an electrical means, for example a motor. The individual connector modules can be brought into an emergency stop condition by the master computer, so that the electrical devices can be brought to a standstill or into a desired condition when malfunctions or safety problems occur. Every connector module comprises a monitoring circuit responsible for this connector module that, given a faulty operation of the processor, resets it into an initial condition and informs the master computer thereof. Such a control and data network is extremely involved; moreover, there is no monitoring of the function and functionability of the electrical devices.
The invention is directed to a monitoring circuit for a multiprocessor means that is utilized in apparatus or systems in order to undertake safety-relevant or reliability-relevant monitorings. For example, the operating condition and the faultless functioning of function elements such as final control elements and generators are monitored. A reliable working of the processors is only guaranteed when all processors participating in a communication are in an identical status at a specific point in time. An appropriate monitoring is extremely involved and is undertaken such that at least two of the processors mutually monitor one another.